Oh! Oh! Me me meeee!
1) You may know this one:
http://www.urban75.com/ - the Useless section has loads of fun things to do.
2)
http://www.superarcade.com/ - This has lots of fun games, including classics like Tetris. This leads me on to:
3)
http://www.adamandjoe.co.uk/songs_listen.php - Liisten to The Tetris Song and The Star Trek song! Very funny! Does anyone remember Adam and Joe? They used to have a show on channel 4, it had 'fiver' style movie bits done using toys as puppets. Stuffed Trek: The Toy Generation is my favourite TV Trek parody ever! Anyway.
4)
http://www.craptv.com/ - This has lots of cool stuff.